1. Field of the Invention
The present invention relates to a process for the manufacture of food products.
2. Description of the Related Art
Such a process is known, for example, from WO-A-95/32633 and BP-A-0 589 820, which describe a process and a system whereby a cooling element with a temperature below 0.degree. C. is immersed in a molten material (such as chocolate) which was previously poured into a mold. The molten material thus solidifies, forming a shell and enabling the cooling element to be extracted from the mold, after serving as a molding plug.
Generally similar arrangements are also known from EP-A-0 914 774 and EP-A-0 914 775.
The shape of the plug enables the chocolate to be evenly distributed inside the mold (forming a shell while still in a fluid state). At the same time, the fact that the plug is cooled enables the chocolate shell to solidify.
In practice, cooling is not normally allowed to continue until the entire mass of the shell solidifies, but only until the portion of chocolate in contact with the plug is solid. The time required for this varies in dependence on the temperature of the plug: usually it takes 4-6 seconds. In other words, the plug is held inside the mold for the time it takes for the portion (or layer) of chocolate in contact with it to solidify, thus enabling it to be detached and extracted.
This technique has various disadvantages, however.
First, the structure of the plug is unavoidably somewhat complex, owing above all to the need to provide the cooling structures, which must be able to follow the movement of the plug.
Secondly, the shape of the plug must complement the internal shape of the product being formed. As a result, the machine must be fitted with a different type of plug when production is changed to a different item.
A further disadvantage is due to the fact that, before extracting the plug and, even more, before being able to do anything to the shell that has just been formed (filling it, for example, or coupling it to a similar shell or the like), it is necessary to wait until the edible material forming the shell is, at least partially, solid. This need to wait for a certain period of time before being able to extract the plug from the mold means that the efficiency of the process is intrinsically low.
The aforesaid disadvantages are particularly significant should the technique be used to manufacture large numbers of items of small dimensions, small hollow chocolate eggs, possibly with a filling, for example.
In this context, it should not be forgotten that the molding material is usually chocolate or a material similar to chocolate, which needs to be cooled in accordance with definite and precise criteria and timing laws, so as to avoid, any anomalous crystallization, for example, which might result in ingredients separating and migrating to the surface.
A further significant disadvantage relates to the possible formation of condensation on the surface of the plug.
Since the plug is cooled to below 0.degree. C., it causes ambient steam to condense onto its surface (forming dew). This problem further delays the removal of the plug and, above all, constitutes a possible, dangerous source of contamination of the product being manufactured: some of the water which accumulates on the plug is in fact deposited on the chocolate shell. For this reason, the structure of the plug is usually housed in a complementary housing maintained at an extremely low relative humidity, thereby further complicating the overall structure of the system in respect of both organization and cost. In any case, this measure does not guarantee that the problem will be eliminated.